Switching in Feedforward Control of Grip Force During Tool-Mediated Interaction With Elastic Force Fields.
Fiche publication
Date publication
janvier 2018
Journal
Frontiers in neurorobotics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr PAPAXANTHIS Charalambos
Tous les auteurs :
White O, Karniel A, Papaxanthis C, Barbiero M, Nisky I
Lien Pubmed
Résumé
Switched systems are common in artificial control systems. Here, we suggest that the brain adopts a switched feedforward control of grip forces during manipulation of objects. We measured how participants modulated grip force when interacting with soft and rigid virtual objects when stiffness varied continuously between trials. We identified a sudden phase transition between two forms of feedforward control that differed in the timing of the synchronization between the anticipated load force and the applied grip force. The switch occurred several trials after a threshold stiffness level in the range 100-200 N/m. These results suggest that in the control of grip force, the brain acts as a switching control system. This opens new research questions as to the nature of the discrete state variables that drive the switching.
Mots clés
grip force, internal model, phase transition, stiffness, uncertainty
Référence
Front Neurorobot. 2018 ;12:31